The animal studies described in this paper were undertaken to determine the mechanisms operating in sudden loss of consciousness following blows to the head. It was anticipated that such an investigation might help to explain the physiology of concussion. In this work emphasis was placed on the study of unconsciousness from simple concussion not associated with intracranial hemorrhage, cerebral laceration or other gross pathologic lesion.
A review of the literature concerning acute unconsciousness from blows on the head shows that there has been little recent investigation. However, many hypotheses have been set forth to explain this unconsciousness.
Cannon, in 1901,1 investigating intracranial pressure following trauma to the head in anesthetized cats, reported that the immediate effect was a sudden increase in the intracranial pressure at the time the injury was received. The author, however, did not indicate the actual intracranial tension developed at the time of the blow. The